Paediatric reference values for the C-terminal fragment of fibroblast-growth factor-23, sclerostin, bone-specific alkaline phosphatase and isoform 5b of tartrate-resistant acid phosphatase

Ann Clin Biochem. 2012 Nov;49(Pt 6):546-53. doi: 10.1258/acb.2012.011274. Epub 2012 Sep 14.


Background: Paediatric reference values for novel markers of phosphate homeostasis, bone formation and resorption and their putative relationship to growth are lacking.

Methods: A total of 424 healthy children, adolescents and young adults (221 males) aged 0.1-21 y, were enrolled in this cross-sectional study. Height, weight and height velocity were assessed. Plasma/serum samples for determination of C-terminal fragment of fibroblast growth factor-23 (cFGF-23), sclerostin, bone alkaline phosphatase (BAP) and tartrate-resistant acid phosphatase 5b (TRAP5b) were available from 222, 264, 352 and 338 individuals, respectively. Calculation of cross-sectional centiles and z-scores was based on median (M), standard coefficient of variation (S) and the Box-Cox power (L) of transformation (LMS method) per age cohort. Correlations between variables as well as with growth were assessed.

Results: cFGF-23, BAP and TRAP5b were significantly correlated with age (each P < 0.01), with highest values during infancy and adolescence. Serum levels of BAP and TRAP5b were significantly higher in adolescent boys compared with girls (each P < 0.01). In contrast, sclerostin levels were independent of age and gender. BAP and TRAP5b were strongly correlated and both were significantly associated with cFGF-23 and sclerostin as well (each P < 0.01). cFGF-23 was positively correlated with serum phosphate and renal phosphate threshold concentration (each P < 0.01). Height, weight, body mass index and height velocity were weakly correlated with BAP and TRAP5b (each P < 0.05).

Conclusions: This study provides age- and gender-related centile charts and z-scores for cFGF-23, BAP, TRAP5b and sclerostin and highlights the link between phosphate homeostasis and markers of bone metabolism during growth.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acid Phosphatase / blood*
  • Acid Phosphatase / urine
  • Adaptor Proteins, Signal Transducing
  • Adolescent
  • Age Factors
  • Alkaline Phosphatase / blood*
  • Alkaline Phosphatase / chemistry
  • Bone Morphogenetic Proteins / blood*
  • Bone Morphogenetic Proteins / urine
  • Bone and Bones / chemistry*
  • Child
  • Child, Preschool
  • Cross-Sectional Studies
  • Female
  • Fibroblast Growth Factors / blood*
  • Fibroblast Growth Factors / urine
  • Genetic Markers
  • Humans
  • Infant
  • Infant, Newborn
  • Isoenzymes / blood*
  • Isoenzymes / urine
  • Male
  • Pediatrics / statistics & numerical data
  • Protein Isoforms / blood
  • Protein Isoforms / chemistry
  • Reference Standards
  • Sex Factors
  • Tartrate-Resistant Acid Phosphatase
  • Young Adult


  • Adaptor Proteins, Signal Transducing
  • Bone Morphogenetic Proteins
  • Genetic Markers
  • Isoenzymes
  • Protein Isoforms
  • SOST protein, human
  • Fibroblast Growth Factors
  • fibroblast growth factor 23
  • Alkaline Phosphatase
  • Acid Phosphatase
  • Tartrate-Resistant Acid Phosphatase